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2. Copeland, C. (2007) ‘Labor force participation: The population age 55 and older’, Employee Benefit Research Institute Notes 28 (6) pp. 2–8.
3. EBRI (Employee Benefit Research Institute) (2008) ‘Sources of income for persons aged 55 and over’, EBRI Databook on Employee Benefits, Chapter 7, Washington, D.C.: EBRI, October.
4. Munnell, A.H. and Sass, S.A. (2007) The labor supply of older Americans, working paper no. 6 (June), Center for Retirement Research, Boston College, Boston, MA.
5. Munnell, A.H., Webb, A. and Delorme, L. (2006) ‘A new national retirement risk index’, An Issue in Brief Center for Retirement Research at Boston College, 48 (June).